So paypal we thought it makes client sense to allow users to prepare their invoice data in an spreadsheet after which they can import it into invoiced. Invoices pay comes with well written & easy card to understand documentation which is accessible from with the application. What good api is an invoicing application if it does not allow to you receive your hard earned cash? we have flexible built invoiced in such a online way that it easily integrates with paypal & stripe. Invoiced comes with a fully functional restful api (info included in billing the documentation) allowing you to integrate invoiced with other applications & / payment or services import. Allowing your invoicing customers to pay their invoices direct online using either their paypal account or their credit card